How Poulan Chain Saw Ignitions Work

Without a working spark plug, it's impossible to start the chain saw.

Understanding the way the ignition system on your Poulan chain saw works makes it easier to troubleshoot if, and when, you ever have a problem starting the machine. Even if you don't run into a problem, the additional knowledge about how a small, two-cycle engine like that on a chain saw works is something that may come in handy when you deal with similar types of engines on other machines commonly found in the garden shed or garage.

Starter

When you pull the handle of the starter cord on the Poulan chain saw, it causes the drive cup to turn the crankshaft and rotate the flywheel. Inside the engine, the piston moves up and down inside its chamber. A problem like a broken starter cord or broken spring inside the starter assembly will prevent the drive cup and flywheel from turning and keep the ignition from firing. Fortunately, replacing the starter cord or the entire starter assembly is a job of which most chain saw users are completely capable.

Ignition Coil

The flywheel that's contained inside the Poulan chain saw has magnets embedded in it. In order to work correctly, the magnets must create a magnetic field with the ignition coil in a carefully timed sequence. When things are working correctly, the interaction between the magnets and the ignition coil produces electricity that reaches the spark plug. When the space between the ignition coil and the flywheel magnets is too large or two small, an interruption in the circuit can stop the engine from starting. A faulty ignition coil can also interrupt the ignition process.

Spark Plug

When the engine is running, the piston moves up and down inside its chamber, drawing in a combination of air, fuel and oil. Two-cycle engines always require that you add engine oil to the gasoline to provide much-needed lubrication to the inner parts of the engine. Failing to do so can cause the engine to seize up. As the piston moves upward and compresses the air and gas combination, the spark plug produces a spark that forces the piston back into a downward motion. Poulan recommends that chain saw operators replace the spark plug every year without fail.

Gas and Air Mixture

In order for the spark plug to ignite inside the piston's chamber, it must receive the correct mixture of fuel and air. When that isn't the case, you may need to adjust the carburetor. When the machine idles too rapidly, signified by chain movement during idle, turn the idle adjustment screw counterclockwise to slow the engine idle down. If the engine tends to sputter and die when idling, turn the idle adjustment screw clockwise to speed up the engine idle and properly adjust the flow of air and fuel into the engine.